Private Branch Exchange, Voip Gateway Unit and Private Branch Exchange System

1. A private branch exchange comprising: a public telephone network connection portion communicatively connected to a public telephone network; a terminal connection portion communicatively connected to a first telephone terminal unit; a park portion configured to park a call put through to said first telephone terminal unit via said terminal connection portion; a control portion controlling said park portion, when a nuisance call from said public telephone network is put through to said first telephone terminal unit via said terminal connection portion, to park said nuisance call on the basis of a prescribed operation of a user against said nuisance call, and parking a call put through to the first telephone terminal unit and thereafter canceling the parking through a second telephone terminal unit, different from the first telephone terminal unit, the control portion allowing the user to talk over the second telephone terminal unit, wherein said park portion is configured to park a prescribed number of calls, and said control portion is configured, when parking a newly received nuisance call in said park portion in a state where said park portion parks said prescribed number of calls, to disconnect any one of said prescribed number of calls parked in said park portion and to thereafter control said park portion to park said newly received nuisance call.

2. The private branch exchange according to claim 1 , further comprising an information storage portion configured to store information related to a caller making a call put through to said telephone terminal unit via said terminal connection portion, wherein said control portion is configured, when said nuisance call is put through to said telephone terminal unit, to control said information storage portion to store information related to a caller making said nuisance call on the basis of said prescribed operation of the user.

3. The private branch exchange according to claim 2 , wherein said control portion is configured, when said nuisance call is put through to said telephone terminal unit, to control said information storage portion to store the telephone number of said caller making said nuisance call as said information related to said caller making said nuisance call on the basis of said prescribed operation of the user.

4. The private branch exchange according to claim 2 , wherein said control portion is configured, when receiving an incoming call from a caller whose said information has been stored in said information storage portion in excess of a prescribed number of times, to perform a prescribed countermeasure operation without putting through said incoming call to said telephone terminal unit.

5. The private branch exchange according to claim 4 , further comprising a list storage portion storing a nuisance call list, wherein said control portion is configured to control said list storage portion to register said caller whose said information has been stored in said information storage portion in excess of said prescribed number of times in said nuisance call list and, when receiving an incoming call from said caller registered in said nuisance call list, to disconnect said incoming call or to transmit warning information to said caller making said nuisance call without putting through said incoming call to said telephone terminal unit.

6. The private branch exchange according to claim 5 , wherein said control portion is configured, when receiving said incoming call from said caller registered in said nuisance call list, to disconnect said incoming call or to transmit said warning information to said caller making said nuisance call without ringing said telephone terminal unit.

7. The private branch exchange according to claim 1 , further comprising a list storage portion storing a nuisance call list, wherein said control portion is configured, when receiving an incoming call from a caller registered in said nuisance call list, to perform a prescribed countermeasure operation without putting through said incoming call to said telephone terminal unit.

8. The private branch exchange according to claim 7 , wherein said control portion is configured, when receiving said incoming call from said caller registered in said nuisance call list, to disconnect said incoming call or to transmit warning information to said caller making said nuisance call without putting through said incoming call to said telephone terminal unit.

9. The private branch exchange according to claim 7 , wherein said nuisance call list stored in said list storage portion is configured to allow the user to rewrite the contents thereof.

10. The private branch exchange according to claim 1 , wherein said control portion is configured, when parking said newly received nuisance call in said park portion in said state where said park portion parks said prescribed number of calls, to disconnect the first parked call among said prescribed number of calls parked in said park portion and to thereafter control said park portion to park said newly received nuisance call.

11. The private branch exchange according to claim 1 , wherein said prescribed operation of the user is an operation of pressing a prescribed button of said telephone terminal unit.

12. The private branch exchange according to claim 1 , wherein said control portion is configured to continuously accept said prescribed operation of the user after a call from said public telephone network is put through to said telephone terminal unit via said terminal connection portion until said call is disconnected.

13. A VoIP gateway unit comprising: a public telephone network connection portion communicatively connected to a public telephone network; a terminal connection portion communicatively connected to a first telephone terminal unit in an IP network; a signal conversion portion converting a voice signal a user can talk over said first telephone terminal unit through said public telephone network; a park portion configured to park a call put through to said first telephone terminal unit via said terminal connection portion; a control portion controlling said park portion, when a nuisance call from said public telephone network is put through to said first telephone terminal unit via said terminal connection portion, to park said nuisance call on the basis of a prescribed operation of the user against said nuisance call, and parking a call put through to the first telephone terminal unit and thereafter canceling the parking through a second telephone terminal unit, different from the first telephone terminal unit, the control portion allowing the user to talk over the second telephone terminal unit, wherein said park portion is configured to park a prescribed number of calls, and said control portion is configured, when parking a newly received nuisance call in said park portion in a state where said park portion parks said prescribed number of calls, to disconnect any one of said prescribed number of calls parked in said park portion and to thereafter control said park portion to park said newly received nuisance call.

14. The VoIP gateway unit according to claim 13 , further comprising an information storage portion configured to store information related to a caller making a call put through to said telephone terminal unit via said terminal connection portion, wherein said control portion is configured, when said nuisance call is put through to said telephone terminal unit, to control said information storage portion to store information related to a caller making said nuisance call on the basis of said prescribed operation of the user.

15. The VoIP gateway unit according to claim 14 , wherein said control portion is configured, when receiving an incoming call from a caller whose said information has been stored in said information storage portion in excess of a prescribed number of times, to perform a prescribed countermeasure operation without putting through said incoming call to said telephone terminal unit.

16. The VoIP gateway unit according to claim 15 , further comprising a list storage portion storing a nuisance call list, wherein said control portion is configured to control said list storage portion to register said caller whose information has been stored in said information storage portion in excess of said prescribed number of times in said nuisance call list and, when receiving an incoming call from said caller registered in said nuisance call list, to disconnect said incoming call or to transmit warning information to said caller making said nuisance call without putting through said incoming call to said telephone terminal unit.

17. A private branch exchange system comprising: a first telephone terminal unit allowing the user to perform a prescribed operation against a nuisance call; and a private branch exchange, wherein said private branch exchange includes a public telephone network connection portion communicatively connected to a public telephone network, a terminal connection portion communicatively connected to said first telephone terminal unit, a park portion configured to park a call put through to said first telephone terminal unit via said terminal connection portion, and a control portion controlling said park portion, when a nuisance call from said public telephone network is put through to said first telephone terminal unit via said terminal connection portion, to park said nuisance call on the basis of said prescribed operation of a user, employing said first telephone terminal unit, against said nuisance call, and parking a call put through to the first telephone terminal unit and thereafter canceling the parking through a second telephone terminal unit, different from the first telephone terminal unit, the control portion allowing the user to talk over the second telephone terminal unit, wherein said park portion is configured to park a prescribed number of calls, and said control portion is configured, when parking a newly received nuisance call in said park portion in a state where said park portion parks said prescribed number of calls, to disconnect any one of said prescribed number of calls parked in said park portion and to thereafter control said park portion to park said newly received nuisance call.

18. The private branch exchange system according to claim 17 , wherein said private branch exchange further includes an information storage portion configured to store information related to a caller making a call put through to said telephone terminal unit via said terminal connection portion, and said control portion is configured, when said nuisance call is put through to said telephone terminal unit, to control said information storage portion to store information related to a caller making said nuisance call on the basis of said prescribed operation of the user.

19. The private branch exchange system according to claim 18 , wherein said control portion is configured, when receiving an incoming call from a caller whose said information has been stored in said information storage portion in excess of a prescribed number of times, to perform a prescribed countermeasure operation without putting through said incoming call to said telephone terminal unit.